The broad objective of the Quantitative Sciences Core is to advance the force and utility of quantitative and, in particular, statistical and mathematical reasoning, modeling and methods among Hopkins Population Center (HPC) associates. The new name for this Core (changed from Mathematical and Statistical Services Core) recognizes the ever-broadening demands by HPC associates for expertise in quantitative science, including mathematical statistics, applied statistics statistical computing, demographic techniques, mathematical demography, econometrics, and psychometrics. The Quantitative Sciences Core will pursue four specific objectives during the next grant period: 1. To serve as quantitative science consultants and collaborators to HPC associates in developing research proposals and conducting population research. 2. To conduct proactive educational programs for HPC associates on state-of-the-art quantitative research methods. 3. To promote the effective use of state-of-the-art statistical software by associates. 4. To advance statistical, mathematical, demographic, and econometric methods to improve the quality of population research. Each of these objectives will strengthen the quality and efficiency of research projects conducted by HPC associates.